1. Technical Field
The present invention relates to thermal therapy systems in general, including therapeutic cooling, heating, and compression systems used in association therewith, and more particularly, but not by way of limitation, to a programmable, sequential compression system adapted for high thermal contrast modality, and incorporating multiple, independently controllable chambers in a thermal therapy blanket.
2. Description of the Related Art
Medical care providers have long recognized the need to provide warmth and cooling directly to patients as part of their treatment and therapy. Better recoveries have been reported using cold therapy for orthopedic patients. The benefits of warming patients undergoing surgery has been conclusively proven. It is also desirable to cool portions of a patient's anatomy in certain circumstances. Yet another advantageous therapy is the application of heat then cold to certain areas of injury.
Several devices have been developed that deliver temperature controlled fluids through pads or convective thermal blankets to achieve the above purpose. Typically these devices have a heating or a cooling element, a source for the fluid, a pump for forcing the fluid through the pad or blanket, and a thermal interface between the patient and the temperature controlled fluid. U.S. Pat. No. 4,884,304 to Elkins is directed to a mattress cover device which contains liquid flow channels which provide the selective heating or cooling by conduction.
Devices have also been developed for providing heat to a person in bed. Electric blankets containing electric heating elements have been used for years to warm a person in bed.
Cooling blankets, such as the blanket disclosed in U.S. Pat. No. 4,660,388 to Greene, have also been proposed. Greene discloses a cooling cover having an inflatable pad with plenum chambers at opposite ends thereof. Cool air is generated in a separate unit and directed to the pad and out a number of apertures on the underside of the pad and against the body of the person using the cover.
A disposable heating or cooling blanket is disclosed in U.S. Pat. No. 5,125,238 to Ragan, et al which has three layers of flexible sheeting. Two of the layers form an air chamber and the third includes a comfortable layer for contact with the patient. Conditioned air is directed toward the covered person through a multiplicity of orifices in the bottom layers of the blanket.
A temperature controlled blanket and bedding assembly is disclosed in commonly assigned U.S. Pat. No. 5,989,285 to DeVilbiss et al., the disclosure of which describes a temperature controlled blanket and temperature control bedding system which has the provision of both recirculating temperature controlled fluid and temperature controlled gas to enhance performance for convectively heating or cooling a patient. Counter-flow or co-flow heat exchanging principles between the temperature controlled liquid and the temperature controlled gas achieve temperature uniformity across different sections of the blanket and the bedding system. Drapes and the temperature controlled bedding system provided temperature controlled envelope around a person using the bedding system. In one embodiment of the bedding system, the air portion of the bedding system is provided for use with a patient that supplies the fluid portion of the overall bedding system. In another embodiment of the bedding system, the fluid portion of the bedding system is provided for use with a patient bed which supplies the air portion of the overall bedding system.
U.S. Pat. No. 5,097,829 to Quisenberry describes an improved temperature controlled fluid circulating system for automatically cooling a temperature controlled fluid in a thermal blanket with a thermoelectric cooling device having a cold side and a hot side when powered by electricity. The temperature controlled fluid is cooled by the cold side of the cooling device and pumped through, to, and from the blanket through first and second conduits.